A separate row has been raging over gay bishops, nearly three years after the Americans sparked fury from African Churches and other traditionalists by ordaining the first openly gay bishop, Gene Robinson of New Hampshire.

The convention in Ohio is under pressure to "repent" of its decision to ordain him, to ban future openly gay bishops and to end the blessing of same-sex unions in church services.

A compromise is being considered to offer repentance only for the effect on the wider Church.

As well as facing possible opposition to her election, Bishop Jefferts Schori faces challenges within the Church too.

Membership has been shrinking for years, and a quarter of the remaining 2.3m parishioners are 65 or older.

Some conservative sections of the Church are also threatening to break away.